class Tins::TempIO::Enum

def initialize(chunk_size: 2 ** 16, filename: nil, &content_proc)
  content_proc or raise ArgumentError, 'need a content proc as block argument'
  super() do |y|
    temp_io(name: 'some-stream', content: content_proc) do |file|
      until file.eof?
        y.yield file.read(chunk_size)
      end
    end
  end.tap do |enum|
    if filename
      enum.define_singleton_method(:filename) do
        filename
      end
    end
  end
end